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Category Archives: Stroke Bypass

Question: We are transporting a patient from a small hospital without a CT scanner to a larger hospital with a CT scanner but not a Stroke Centre. Our patient is an obvious stroke patient...slurred speech for over 1 day, but is getting better and no other issues...stable, but still with slurred speech (does not meet Stroke Protocol as onset over 24hrs). What should we do should this patient become worse enroute to the CT capable hospital? Say his slurred speech becomes worse or he shows other signs and symptoms? Is this considered a "new onset" or a continuation of his current CVA/TIA? If "new onset" I would think he now meets the Stroke Protocol and should be diverted to the Stroke Centre? Could you please clarify?

Answer: Clinically, possibly one of many things is happening:
1) A 2nd embolic event
2) Progression of an original hemorrhagic stroke
3) Conversion of an ischemic stroke to a hemorrhagic stroke
4) Swelling around a space occupying lesion,(tumour or abscess, focal seizure)
5) A unrelated metabolic change (hypoglycemia, hyponatremia, hypoxia etc).

At the end of the day it doesn’t matter much for this call…. it is an inter-facility transfer. (The Provincial Stroke Protocol does not apply to inter facility transfers) You should contact the sending physician and the receiving center and alert them of the status change. The findings you have found may change the management. The noncontrast CT head, maybe changed to with and without contrast to help better elucidate the cause, and this may effect final destination. Depending upon findings this patient may need a neurosurgical center, some smaller regional stoke centers do not have neurosurgical capability (Chatham, Stratford, etc).This patient will require stabilization and medical reassesment. They may require further resources for ongoing transport. Communication is essential in these dynamic cases.

It would also be highly unlikely that this patient would qualify for TPA (the ultimate reason behind a proposed diversion to the Stroke Centre) given that the neuro symptoms you are describing have been present for over 24h. The bleeding complications associated with TPA in that scenario would outweigh any possible benefit.

Question: I don't agree with the transport consideration in case study #1 of the Acute Stroke Protocol that states the patient is excluded from transport to a Designated Stroke Centre due to not being able to determine onset of symptoms: male, age 58, found unconscious on the floor at 0800 by a friend, when he came to pick him up for work. Shouldn't we consider it likely the symptom onset was < 3.5hrs especially in this case where it would be safe to assume symptom onset probably occurred after patient got up to get ready for work and that he probably does not get up three and a half hours prior to getting picked up at 0800. Further, it's more likely his GCS would be worse than 10 had he been down much longer. Bottom line, shouldn't we be erring on the side of caution for these patients and give them the benefit of the doubt that symptom onset might be < 3.5hrs given the evidence at hand? Or even with less evidence? As an aside, is the time going to be extended as i believe some doctors think it should?

Answer: Thanks for the question. We are sorry that you don’t agree with the current Stroke Guidelines.

The stipulation that the patient must arrive to a Designated Stroke Centre within 3.5h of a clearly determined time of symptom onset or the time the patient was “last seen in a usual state of health” is one of the most common questions we receive from paramedics. Interestingly, this is also one of the most common protocol violations from the Paramedic Prompt Card for Acute Stroke Protocol and one of the most common complaints the Stroke Neurologists refer back to the Base Hospital for investigation.

The Prompt Card was created from a joint working group of neurologists and emergency physicians and is designed to reflect the latest in clinical practice.

Unfortunately, we know from experience that as soon as we vary from the very strict protocols for thrombolysis, the frequency of complications (and specifically intra-cerebral hemorrhage) increases. Evidence for this can be found here: http://stroke.ahajournals.org/content/32/1/12.full.pdf+html

In reference to your comments that the current evidence suggests that the time window should be increased again, while this may occur in the future as experience with thrombolysis for stroke grows, the latest update from the American Heart Association clearly suggests that the current practice in Ontario in consistent with best practice. The AHA guidelines for stroke can be found here: http://circ.ahajournals.org/content/122/18_suppl_3/S818.full.pdf+html

Bottom line: Your suggestion of erring on the side of caution and giving the patient in the case you describe the benefit of doubt may actually increase their risk of harm from TPA.

A couple of points about your case: You describe a patient suffering from a stroke as being unconscious. Remember, most often, patients need to have a bi-hemispheric insult to their brain in order to be unconscious. Given the duplicate bilateral vascular supply the brain receives, it is not common for a true ischemic stroke patient to be unconscious. The altered GCS (< 10) on the Prompt Card is designed to allow a patient to have completely lost speech (complete aphasia = 1 out of 5) and still be a candidate for “Stroke Bypass”. A further fall of 2 points to < 10 would suggest that another process is in place affecting the patients level of consciousness. It is not clear that the length of time lying on the floor can be directly or accurately linked to level of consciousness as you suggest.

Finally, from a patient safety point of view, it is also not clear that transporting unconscious patients for up to two hours to a designated stroke centre can be done safely without advanced airways and/or other interventions. This may also further increase the risk of harm to patients.

Question: Recently, after transporting a stroke bypass patient we were told they could not be treated for the stroke (with thrombolytic) due to the patient's history of warfarin use. How does this fall under our protocol but outside theirs? If blood thinners (either in conjunction with a specific disease or as a certain dose) are a roadblock to thrombolytic therapy why isn't it listed as a contraindication to the bypass protocol? We did not have time to discuss the rationale behind the statement and have been wondering since if we misinterpreted the statement or if warfarin and similar drugs really do prevent thrombolytic use with CVA's? I know there have been studies linking problems with tPA in patients with warfarin history but didn't know that played an active role in the exclusion criteria at stroke centers now. If this is the case why not change the protocol to eliminate needless transport (especially when transporting from outside of the city/county where the center is located?

Answer: Great question! As you know, the Stroke Bypass program inclusion criteria are created out of a joint working group which includes EMS physicians and stroke neurologists as part of the Ontario Stroke Strategy. Last Spring, Dr Lewell actually presented an update both in London and in Huron County on this topic and this very question was addressed.

You are absolutely correct, when giving tPA, there is an increased risk of bleeding, specifically intracerebral bleeding, if the patient is already anticoagulated from taking Warfarin. However until the INR is measured, the practitioner has no way of knowing whether the patient’s blood is “too thin” or not to receive tPA. Therefore although most patients who take Warfarin will not be candidates to receive tPA, some will be and there is no way of telling who that is until they are assessed at a Stroke Centre. So taking Warfarin does not automatically exclude a patient from being transported on Stroke Bypass.

The other answer from the stroke neurologists who actually insist that these patients on warfarin are transported to the stroke centre is that these patients may not be compliant with their medications. If this was the case, the coagulation profile may actually be completely within the normal range thus enabling this subset of patients to still receive TPA. In fact, it very well may be that warfarin non compliance may be the actual cause of an embolic stroke in a patient with atrial fibrillation and as such, failure to transport these patients to a stroke centre capable of administering TPA could have devastating consequences.